"Já ho za dobrého otce nepovažuju."

Translation: I do not consider him a good father.

[btopps]

How exactly is "za" translated here?

[VladaFu]

You cannot translate every word. Different verbs have different kind of valences in different languages. "to consider somebody something" is "považovat někoho za něco". It is just a preposition used with the verb.

[ken55414]

In this case, does "za" require accusative or genitive?

[VladaFu]

accusative, genitive would be něčeho, not něco